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mastodon/app/controllers/concerns/signature_verification.rb

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# frozen_string_literal: true
# Implemented according to HTTP signatures (Draft 6)
# <https://tools.ietf.org/html/draft-cavage-http-signatures-06>
module SignatureVerification
extend ActiveSupport::Concern
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include DomainControlHelper
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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EXPIRATION_WINDOW_LIMIT = 12.hours
CLOCK_SKEW_MARGIN = 1.hour
class SignatureVerificationError < StandardError; end
class SignatureParamsParser < Parslet::Parser
rule(:token) { match("[0-9a-zA-Z!#$%&'*+.^_`|~-]").repeat(1).as(:token) }
rule(:quoted_string) { str('"') >> (qdtext | quoted_pair).repeat.as(:quoted_string) >> str('"') }
# qdtext and quoted_pair are not exactly according to spec but meh
rule(:qdtext) { match('[^\\\\"]') }
rule(:quoted_pair) { str('\\') >> any }
rule(:bws) { match('\s').repeat }
rule(:param) { (token.as(:key) >> bws >> str('=') >> bws >> (token | quoted_string).as(:value)).as(:param) }
rule(:comma) { bws >> str(',') >> bws }
# Old versions of node-http-signature add an incorrect "Signature " prefix to the header
rule(:buggy_prefix) { str('Signature ') }
rule(:params) { buggy_prefix.maybe >> (param >> (comma >> param).repeat).as(:params) }
root(:params)
end
class SignatureParamsTransformer < Parslet::Transform
rule(params: subtree(:param)) do
(param.is_a?(Array) ? param : [param]).each_with_object({}) { |(key, value), hash| hash[key] = value }
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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end
rule(param: { key: simple(:key), value: simple(:val) }) do
[key, val]
end
rule(quoted_string: simple(:string)) do
string.to_s
end
rule(token: simple(:string)) do
string.to_s
end
end
def require_account_signature!
render plain: signature_verification_failure_reason, status: signature_verification_failure_code unless signed_request_account
end
def require_actor_signature!
render plain: signature_verification_failure_reason, status: signature_verification_failure_code unless signed_request_actor
end
def signed_request?
request.headers['Signature'].present?
end
def signature_verification_failure_reason
@signature_verification_failure_reason
end
def signature_verification_failure_code
@signature_verification_failure_code || 401
end
def signature_key_id
signature_params['keyId']
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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rescue SignatureVerificationError
nil
end
def signed_request_account
signed_request_actor.is_a?(Account) ? signed_request_actor : nil
end
def signed_request_actor
return @signed_request_actor if defined?(@signed_request_actor)
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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raise SignatureVerificationError, 'Request not signed' unless signed_request?
raise SignatureVerificationError, 'Incompatible request signature. keyId and signature are required' if missing_required_signature_parameters?
raise SignatureVerificationError, 'Unsupported signature algorithm (only rsa-sha256 and hs2019 are supported)' unless %w(rsa-sha256 hs2019).include?(signature_algorithm)
raise SignatureVerificationError, 'Signed request date outside acceptable time window' unless matches_time_window?
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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verify_signature_strength!
verify_body_digest!
actor = actor_from_key_id(signature_params['keyId'])
raise SignatureVerificationError, "Public key not found for key #{signature_params['keyId']}" if actor.nil?
signature = Base64.decode64(signature_params['signature'])
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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compare_signed_string = build_signed_string
return actor unless verify_signature(actor, signature, compare_signed_string).nil?
actor = stoplight_wrap_request { actor_refresh_key!(actor) }
raise SignatureVerificationError, "Public key not found for key #{signature_params['keyId']}" if actor.nil?
return actor unless verify_signature(actor, signature, compare_signed_string).nil?
fail_with! "Verification failed for #{actor.to_log_human_identifier} #{actor.uri} using rsa-sha256 (RSASSA-PKCS1-v1_5 with SHA-256)"
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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rescue SignatureVerificationError => e
fail_with! e.message
rescue HTTP::Error, OpenSSL::SSL::SSLError => e
fail_with! "Failed to fetch remote data: #{e.message}"
rescue Mastodon::UnexpectedResponseError
fail_with! 'Failed to fetch remote data (got unexpected reply from server)'
rescue Stoplight::Error::RedLight
fail_with! 'Fetching attempt skipped because of recent connection failure'
end
def request_body
@request_body ||= request.raw_post
end
private
def fail_with!(message)
@signature_verification_failure_reason = message
@signed_request_actor = nil
end
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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def signature_params
@signature_params ||= begin
raw_signature = request.headers['Signature']
tree = SignatureParamsParser.new.parse(raw_signature)
SignatureParamsTransformer.new.apply(tree)
end
rescue Parslet::ParseFailed
raise SignatureVerificationError, 'Error parsing signature parameters'
end
def signature_algorithm
signature_params.fetch('algorithm', 'hs2019')
end
def signed_headers
signature_params.fetch('headers', signature_algorithm == 'hs2019' ? '(created)' : 'date').downcase.split(' ')
end
def verify_signature_strength!
raise SignatureVerificationError, 'Mastodon requires the Date header or (created) pseudo-header to be signed' unless signed_headers.include?('date') || signed_headers.include?('(created)')
raise SignatureVerificationError, 'Mastodon requires the Digest header or (request-target) pseudo-header to be signed' unless signed_headers.include?(Request::REQUEST_TARGET) || signed_headers.include?('digest')
raise SignatureVerificationError, 'Mastodon requires the Host header to be signed when doing a GET request' if request.get? && !signed_headers.include?('host')
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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raise SignatureVerificationError, 'Mastodon requires the Digest header to be signed when doing a POST request' if request.post? && !signed_headers.include?('digest')
end
def verify_body_digest!
return unless signed_headers.include?('digest')
raise SignatureVerificationError, 'Digest header missing' unless request.headers.key?('Digest')
digests = request.headers['Digest'].split(',').map { |digest| digest.split('=', 2) }.map { |key, value| [key.downcase, value] }
sha256 = digests.assoc('sha-256')
raise SignatureVerificationError, "Mastodon only supports SHA-256 in Digest header. Offered algorithms: #{digests.map(&:first).join(', ')}" if sha256.nil?
return if body_digest == sha256[1]
digest_size = begin
Base64.strict_decode64(sha256[1].strip).length
rescue ArgumentError
raise SignatureVerificationError, "Invalid Digest value. The provided Digest value is not a valid base64 string. Given digest: #{sha256[1]}"
end
raise SignatureVerificationError, "Invalid Digest value. The provided Digest value is not a SHA-256 digest. Given digest: #{sha256[1]}" if digest_size != 32
raise SignatureVerificationError, "Invalid Digest value. Computed SHA-256 digest: #{body_digest}; given: #{sha256[1]}"
end
def verify_signature(actor, signature, compare_signed_string)
if actor.keypair.public_key.verify(OpenSSL::Digest.new('SHA256'), signature, compare_signed_string)
@signed_request_actor = actor
@signed_request_actor
end
rescue OpenSSL::PKey::RSAError
nil
end
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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def build_signed_string
signed_headers.map do |signed_header|
if signed_header == Request::REQUEST_TARGET
"#{Request::REQUEST_TARGET}: #{request.method.downcase} #{request.path}"
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
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elsif signed_header == '(created)'
raise SignatureVerificationError, 'Invalid pseudo-header (created) for rsa-sha256' unless signature_algorithm == 'hs2019'
raise SignatureVerificationError, 'Pseudo-header (created) used but corresponding argument missing' if signature_params['created'].blank?
"(created): #{signature_params['created']}"
elsif signed_header == '(expires)'
raise SignatureVerificationError, 'Invalid pseudo-header (expires) for rsa-sha256' unless signature_algorithm == 'hs2019'
raise SignatureVerificationError, 'Pseudo-header (expires) used but corresponding argument missing' if signature_params['expires'].blank?
"(expires): #{signature_params['expires']}"
else
"#{signed_header}: #{request.headers[to_header_name(signed_header)]}"
end
end.join("\n")
end
def matches_time_window?
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
2020-08-24 18:21:07 +02:00
created_time = nil
expires_time = nil
begin
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
2020-08-24 18:21:07 +02:00
if signature_algorithm == 'hs2019' && signature_params['created'].present?
created_time = Time.at(signature_params['created'].to_i).utc
elsif request.headers['Date'].present?
created_time = Time.httpdate(request.headers['Date']).utc
end
expires_time = Time.at(signature_params['expires'].to_i).utc if signature_params['expires'].present?
rescue ArgumentError
return false
end
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
2020-08-24 18:21:07 +02:00
expires_time ||= created_time + 5.minutes unless created_time.nil?
expires_time = [expires_time, created_time + EXPIRATION_WINDOW_LIMIT].min unless created_time.nil?
return false if created_time.present? && created_time > Time.now.utc + CLOCK_SKEW_MARGIN
return false if expires_time.present? && Time.now.utc > expires_time + CLOCK_SKEW_MARGIN
true
end
def body_digest
@body_digest ||= Digest::SHA256.base64digest(request_body)
end
def to_header_name(name)
name.split(/-/).map(&:capitalize).join('-')
end
Add support for latest HTTP Signatures spec draft (#14556) * Add support for latest HTTP Signatures spec draft https://www.ietf.org/id/draft-ietf-httpbis-message-signatures-00.html - add support for the “hs2019” signature algorithm (assumed to be equivalent to RSA-SHA256, since we do not have a mechanism to specify the algorithm within the key metadata yet) - add support for (created) and (expires) pseudo-headers and related signature parameters, when using the hs2019 signature algorithm - adjust default “headers” parameter while being backwards-compatible with previous implementation - change the acceptable time window logic from 12 hours surrounding the “date” header to accepting signatures created up to 1 hour in the future and expiring up to 1 hour in the past (but only allowing expiration dates up to 12 hours after the creation date) This doesn't conform with the current draft, as it doesn't permit accounting for clock skew. This, however, should be addressed in a next version of the draft: https://github.com/httpwg/http-extensions/pull/1235 * Add additional signature requirements * Rewrite signature params parsing using Parslet * Make apparent which signature algorithm Mastodon on verification failure Mastodon uses RSASSA-PKCS1-v1_5, which is not recommended for new applications, and new implementers may thus unknowingly use RSASSA-PSS. * Add workaround for PeerTube's invalid signature header The previous parser allowed incorrect Signature headers, such as those produced by old versions of the `http-signature` node.js package, and seemingly used by PeerTube. This commit adds a workaround for that. * Fix `signature_key_id` raising an exception Previously, parsing failures would result in `signature_key_id` being nil, but the parser changes made that result in an exception. This commit changes the `signature_key_id` method to return `nil` in case of parsing failures. * Move extra HTTP signature helper methods to private methods * Relax (request-target) requirement to (request-target) || digest This lets requests from Plume work without lowering security significantly.
2020-08-24 18:21:07 +02:00
def missing_required_signature_parameters?
signature_params['keyId'].blank? || signature_params['signature'].blank?
end
def actor_from_key_id(key_id)
domain = key_id.start_with?('acct:') ? key_id.split('@').last : key_id
if domain_not_allowed?(domain)
@signature_verification_failure_code = 403
return
end
if key_id.start_with?('acct:')
stoplight_wrap_request { ResolveAccountService.new.call(key_id.gsub(/\Aacct:/, ''), suppress_errors: false) }
elsif !ActivityPub::TagManager.instance.local_uri?(key_id)
account = ActivityPub::TagManager.instance.uri_to_actor(key_id)
account ||= stoplight_wrap_request { ActivityPub::FetchRemoteKeyService.new.call(key_id, id: false, suppress_errors: false) }
account
end
rescue Mastodon::PrivateNetworkAddressError => e
raise SignatureVerificationError, "Requests to private network addresses are disallowed (tried to query #{e.host})"
rescue Mastodon::HostValidationError, ActivityPub::FetchRemoteActorService::Error, ActivityPub::FetchRemoteKeyService::Error, Webfinger::Error => e
raise SignatureVerificationError, e.message
end
def stoplight_wrap_request(&block)
Stoplight("source:#{request.remote_ip}", &block)
.with_threshold(1)
.with_cool_off_time(5.minutes.seconds)
.with_error_handler { |error, handle| error.is_a?(HTTP::Error) || error.is_a?(OpenSSL::SSL::SSLError) ? handle.call(error) : raise(error) }
.run
end
def actor_refresh_key!(actor)
return if actor.local? || !actor.activitypub?
return actor.refresh! if actor.respond_to?(:refresh!) && actor.possibly_stale?
ActivityPub::FetchRemoteActorService.new.call(actor.uri, only_key: true, suppress_errors: false)
rescue Mastodon::PrivateNetworkAddressError => e
raise SignatureVerificationError, "Requests to private network addresses are disallowed (tried to query #{e.host})"
rescue Mastodon::HostValidationError, ActivityPub::FetchRemoteActorService::Error, Webfinger::Error => e
raise SignatureVerificationError, e.message
end
end